Most common inkjet cartridge remanufacturing processes involve a number of typical steps and that take place in various stages.
Preparation Stage
Often times a used, typically empty cartridge is stored without any cover on the print head such as a clip or a tape for a prolonged period of time (months or sometimes years). As a result the used ink residues get dried in the firing chambers and between the filter and the print head and causes blockage of the ink path. In the preparation stage, the used cartridge is thoroughly washed and cleaned in order to remove as much as possible the dried original ink residues. The used cartridge is then dried to avoid dilution of water and dilution of new ink that later fills the remanufactured cartridge.
Also, during the preparation stage, on some occasions, depending on the model and type of cartridge, the cap is removed, and on some occasions the foam is removed, washed and dried or replaced by a new cap. On some occasions, depending on the cartridge model, the filter screen is removed and a new filter is welded on the ink delivery tunnel. It is believed that there is no remanufacturing process that involves removing the used print head assembly and installing a new print head assembly.
Filling Stage
In the filling stage the foam is put back into the cartridge, in case it was removed and the cartridge is filled with new ink. It is believed that there are two major filling techniques. First, in the no vacuum filling technique, a needle is inserted into the foam inside the cartridge and a pump or manually filling with a syringe is employed to dispense the ink. The second technique involves filling the cartridge under vacuum conditions. In this technique the cartridge is put inside a vacuum chamber that generates vacuum in order to assure that no air bubbles are trapped in the ink path. The trapped bubbles can block the ink path and cause local print failure. The ink is dispensed into the foam inside the cartridge while the cartridge is under vacuum conditions, and then the vacuum is slowly released, and the cartridge is then taken out of the chamber.
Printing Stage
In the printing stage the remanufactured cartridge's print quality is tested by placing the cartridge in a printer and printing a few sample pages in order to evaluate the quality of the print.
Packaging Stage
In the packaging stage the remanufactured cartridge is re-labeled, cleaned, sealed and boxed. The print head assembly in an inkjet printer cartridge is in charge of dispensing the ink directly on the printed media. The print head is a combination of microscopic dispensing chambers. Each chamber has an embedded resistor that is electrically connected to contacts on the print head assembly's flexible board. Upon receiving a signal from the printer, the resistor heats up for a predetermined period. The heating of the embedded resistor inside each chamber causes local boiling of the ink that is its surroundings, and the heating action creates an air bubble of water vapor that pushes the ink inside the chamber through a firing nozzle in the opposite direction of the resistor onto the printed media. The combination of thousands or millions of microscopic drops on the printed media creates the image.
There are several reasons that cause the print head assembly not to fire up or not to fire up effectively for an ink jet drop. One of the possible reasons for failure of the ink chamber is electrical discontinuity of the resistor from the flexible board at some point due to mechanical damage or excessive temperature cycles. Another possible failure is accumulation of dry ink over the resistor during the lifecycle of the cartridge or in storage that will disrupt the required heat exchange between the resistor and the ink in the chamber to generate the vapor bubble in a timely manner. Yet another possible reason for failure of the chamber would be mechanical damage such as scratch or a ding to the surface of the nozzle plate that prevents the ink bubble from flowing out of the ink chamber. Yet another possible reason for failure is the drying of ink inside the ink chamber that disrupts the delivery of ink from the main reservoir in the cartridge to the chamber. Yet another possible reason for failure is an original cartridge design deliberately made by the original manufacturer. In such designs the original circuit is designed to discharge a significant current from a capacitor into the print head circuitry once the cartridge is depleted, with sufficient current to thus burn or fuse the relatively delicate electrical conduits or traces in the print head and cause subsequent malfunction of the heat resistors, as described in U.S. Pat. No. 6,099,101. All of the above examples will produce one or more white lines across the printed media, often times called “streaking”.
The vast majority of defects or problems with original or used cartridge that are used in an inkjet cartridge remanufacturing process can be traced to one or more of the above described examples. Thus, without replacing the print head assembly of a depleted, once used, inkjet cartridge a significant amount of failures cannot be avoided.
To address the above-described problems the present methods are directed to removing used print heads from a used, original inkjet cartridge and installing a new inkjet print head assembly over the used inkjet cartridge's container.